Integration of terrestrial laser scanning and GIS analysis for multi-temporal landslide monitoring: A case study of the Mont de La Saxe (Aosta Valley, NW Italy)

In Italy, landslide phenomena and mass movements are very common, particularly along the Alps, the principal mountainous chains in the northern part of the country. In this study, we used a terrestrial laser scanner (TLS) to collect a multi-temporal dataset during 3 years (2012–2014) of observation, with the aim of accurately evaluating these phenomena in the Mont de la Saxe area (Aosta Valley region, Italy). Starting from the point clouds acquired with the TLS, we derived the digital surface models and we performed a multitemporal analysis in geographical information system (GIS) to identify the morphological features of the landslide and to delineate the displacement of the phenomena. The analysis allows quantifying the major elevation change occurred in the middle and the bottom side of landslide body during 2012–2014 with a high precision. The volume displaced in the second year (2013–2014) increased by 66% than the previous year (2012–2013), showing a progressive acceleration of the landslide phenomena. This result indicates that the volume estimation is crucial for planning future landslide emergency situations and to calibrate the early warning system, based on occurred phenomena.